Furnace.



No- 826,406. PATENTED JULY 1'7, 1906.

. W. N. 00X.

FURNACE.

APPLICATION FILED JUNE 15. 1904.

3 SHEETS-SHEET l.

THE NDRRIS PETERS co., WASHINGTON. n. c.

AM I No. 826,405. PATENTBD JULY 17, 1906. W. N. 00X.

FURNACE.

APPLICATION FILED JUNE 15, 1904.

a BHEBTS-SHEL'I. z.

1n: NORRIS PETERS ca, WASHINGTON, D. c.

PATENTED JULY 17 W. N. COX.

FURNACE.

APPLICATION FILED JUNE 15, 1904.

3 SHEETS-SHEET 3;

III

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

PatentedJ'uly 17, 1906.

Application filed June 15,1904. $erial N0. 212,738-

To all whom it may concern:

Be it known that 1, WILLIAM N. Cox, a citizen of the United States, residing at Montgomery, in the county of Montgomery and State of Alabama, have invented new and useful Improvements in Furnaces, of which the following is a specification.

This invention relates to improvements in furnaces, and particularly to draft apparatus therefor.

The object in view is the provision of means for obtaining the highest possible degree of perfection of combustion, and this object is attained by the employment of means in combination with a fire-box for supplying heated air to such fire-box during a charging operation and means for decreasing said airsupply gradually after the completion of such charging operation.

With the above-mentioned and other objects in view the invention comprises certain novel constructions, combinations, and arrangements of parts, as will be hereinafter fully described and claimed.

In the accompanying drawings, Figure 1 represents a longitudinal vertical central section taken through a boiler-furnace embodying the features of the present invention, the boiler being illustrated in elevation. Fig. 2 represents a view in front elevation of the same. Fig. 3 represents a transverse vertical section taken on the plane of line 3 3 of Fig. 1 and looking in the direction of the arrow. Fig. 4 represents an enlarged detail longitudinal vertical central section through the steam-controlling valve detached. Fig. 5 represents an enlarged sectional view of the valve controlling the pressure actuating the piston of the valve shown in Fig. 4. Fig. 6 is a horizontal section taken on the plane at right angles to the plane of the section of Fig. 4.

In the present art it is found desirable to supply heated air to the products of combusion rising from the fire-box of a furnace in order that the gases may be perfectly consumed and the greatest number of heat units thus obtained from a minimum amount of fuel, and in order to accomplish this desirable end I employ elements such as are seen in the accompanying drawings, in which 1 indicates a casing, preferably of the ordinary masonry type, forming a firebox 2, provided with any suitable grate 3 and a heatchamber 4 in the rear of the fire-box and divided therefrom by a hollow bridge-wall 5.

Extending transversely through the bridgewall 5 and communicating at one end with the fire-box 2 and at the other end with the heating-chamber 4 are relatively large drafteyes 6 6 and a relatively small draft-eye 7, the relatively large eyes being arranged beneath and at the sides of the boiler 8, mounted within the casing 1, and the relatively small draft-eye 7 being positioned in the vertical plane of the longitudinal axis of the said boiler. Each of the eyes 6 and 7 is formed near that end communicating with the firebox 2 with a plurality of apertures 9, communicating with the interior of the bridgewall 5, and each of said draft-eyes is formed at its opposite end with a tapered portion 10, followed by a flared portion 11.

An air-supply pipe 11 penetrates the rear wall of the casing 1 and extends upwardly within the heat-chamb er 4 and longitudinally of the boiler 8 within the steam-space thereof, through the front head of the boiler, and to a point just above the feeding-doors 1-2 12 of the fire-box 2. A cross-pipe 13 communicates with the end of the pipe 11, extending below the head of the boiler 8, and said crosspipe is provided with a plurality of nozzles 14, leading downwardly into the fire-box 2. The pipe 13 at its ends communicates with pipes 15 15, extending into the casing 1 at the respective sides thereof, the inner ends of the pipes 15 opening into the interior of the hollow bridge-wall 5. Extending from the steam-dome of the boiler Sis a steam-pipe 16, communicating with the pipe 17, arranged parallel to pipe 13 and provided with nozzles 18 18, discharging longitudinally through the nozzles 14. The pipe 17 communicates at its ends with pipes 19 19, extending longitudinally of the respective pipes 15. Each of the pipes 15 is provided intermediate its length within the fire-box with laterally-projecting nozzles 20 20, arranged to discharge into the fire-box 2 above the grate 3, and each of the respective pipes 19 within the given pipe 1.5 is provided with nozzles 21, arranged to discharge through each of the nozzles 20, a similar nozzle 21 being provided for the ends of the pipes 15, discharging into the hollow bridgewall. Intermediate the length of the pipe 16 is arranged a steam-controlling valve 22, (seen in detail in Fig. 4,) said valve consisting of a casing provided with an intake-opening 23 for the pipe 16 and a discharge-opening 24 for said pipe. A piston 25 is movably mounted within the of valve 22.

case. The piston 25 is pressed from the rear by a spring 26, interposed between said piston and the end of the valve-casing, and a valve 27 is connected with the piston 25 in front of the same by means of a suitable bolt 28, threaded into said piston and having its head lying within a notch formed in the valve '27. A pin 29 is arranged transversely of the casing for limiting the valve 27 against lat eral play and for causing the same to close the discharge-opening 24 when the piston 25 is moved under the action of the spring and the steam admitted through a port 30, formed in the casing in the rearof the piston 25. As seen in Fig. 2, a tube 31 leads from the pipe 16 above the valve 22 to a point contiguous to one of the doors 12 and there communicates with a three-way valve 32 (seen best in Fig. 5) and controlled in its operation and adapted to be actuated by a link 33, connected with the door 12. A pipe 33 communicates with the valve 32 at one end and at the other end communicates with port 30 The three-way valve 32 (seen in Fig. 5) is provided with a main bore relatively wide at the point of communication of pipe 33 with the casing and relatively narrow at the point of communication of pipe 31 with the casing, whereby the valve 32 may be turned until communication with pipe 31 is cut off, and the pipe 33 will still communicate with the main bore of the valve 32. The by-pass 32 leads from the main bore of the valve 32 to one side of the casing and is adapted to register with an aperture in the casing in position for having the said bypass register therewith after the communication with pipe 31 has been cut off, whereby rotation of the valve 32 in one direction is adapted to open communication between the pipes 31 and 33, and rotation of said valve in the other direction is designed to close such communication and open communication between the pipe 33 and the atmosphere. Thus the ports in valve 32 are so arranged as when the door 12 is closed to establish communication between pipe 31 and pipe 33; but when said door is open the valve is rotated to the position cutting off the communication of pipe 31 and establishing communication between pipe 33 and theatmosphere, so that it will be seen that when the door 12 is closed steam admitted through pipes 31 and 33 will enter the casing of valve 22 in the rear of piston 25 and will balance the pressure of steam admitted through opening 23, causing the piston 25 to move forwardly under the pressure of spring 26 until the valve 27 closes the opening 24. hen, however, the door 12 is opened and the steam in the rear of the piston 25 is exhausted through pipe 33 and by-pass 32 of valve 32, the steam-pressure entering opening 23 will be of sufficiently greater strength than spring 26 to overcome ,the same and to cause piston 25 to move rearwardly, effecting a similar movement of the valve 27 and permitting the admission of steam through the discharge-opening 24. It is to be observed that, as seen in Fig. 5, the discharge-opening of the three-way valve 32 is of sufficient size relative to port 30 to permit ready exhaust of steam from the rear of piston 25 when the door 12 is opened,

'whereby an almost immediate supply of steam is afforded the pipe 17 and the nozzles supplied thereby. The port 30 is relatively small with respect to intake-opening 23, and therefore when the door 12 is closed the steam supplied therethrough will by the aid of spring 26 slowly overcome the pressure of the steam admitted through port 23 and piston 25 will not be suddenly affected, but will be gradually moved to a position for closing opening 24. Thus when the door 12 is closed the supply of steam to pipe 17 will gradually decrease, and the discharge of steam through nozzles 18 and 21 will decrease in a similar manner, and as such discharge is depended upon for producing a forced draft within the tube 11 it will be seen that when the door 12 is opened a maximum supply of air will be delivered to the fire -box and when the door is closed the supply will gradually decrease until the supply of air entirely ceases.

While I have disclosed but a single furnace in the drawings, it will be understood that in practice I propose to arrange a battery of boilers and furnaces disposed laterally with respect to each other, each of the furnaces and boilers being constructed like the furnace and boiler illustrated and each being provided with a stack 34 for the products of combustion, a horizontally-disposed flue 35 being arranged transversely with respect to the stacks 34 and designed to supply air thereto, communication between the flue 35 and the re spective stack 34 being controlled by means of a damper 36, normally closing the opening in the respective stack 34, formed for establishing communication between the said flue and stack. The damper 36 is arranged in suitable guide'ways 37 37 and adapted to be moved vertically for establishing communication between the flue 35 and the stack 34, the flue 35 being employed to prevent the escape of smoke into the furnace-room in case of leaking past the damper 36. A piston-rod 38 is connected at its upper end to the lower end of the damper 36 and extends downwardly into a cylinder 39 and carries at its lower end a piston 40, designed to be actuated by steam-pressure admitted to the lower end of the cylinder 39 from either of the pipes 41 or 42. The pipes 41 and 42 communicate with branch pipes 43 and 44, re spectively, each of said branch pipes communicating with the pipe 17 and being provided with a valve 45, interposed between the pipe 17 and the respective pipe 41 or 42. Each ICC valve 45 is connected by a link 46 with one of the doors 12 and is adapted to beopened when the respective door is opened and closed when the door is closed through said connection. A relief-valve 46 is arranged at the end of each of the pipes 43 and 44 outside the communication thereof with the respective pipe 41 or 42, each of said relief-valves being designed to be left open to a slight extent, so that in practice When one of the valves 45 is opened the steam will be admitted to the respective pipe 41 or 42 and thence to the cylinder 39 but at the same time a certain amount of the steam will be escaping through the respective relief-valve 46, but suflicient steam will be admitted to the cylinder 39 for causing the piston 40 to rise and elevate the damper 36 for permitting the establishment of communication between the flue 35 and the stack 34, it being understood, of course, that the flue 35 is supplied with air. as the respective door 12 is closed and the corresponding valve 45 is closed the respective relief-valve 46 will permit the exhaust of steam from within the cylinder 39, and thereby permit the dropping of the damper 36 to its normal closed position.

It will be observed that the bottom of the boiler 8 must necessarily be of considerable lower temperature than that of the flame passing through the draft-eyes 6 and 7, and hence the particular structure of said eyes and positioning of the same, for it is my object to avoid contact of the said flame with the boiler to as great an extent as possible, such contact producing carbonization and a proportional decrease in the efficiency of combustion. I have therefore positioned the eyes 6 6 and 7 at approximately equal distances from the boiler and have arranged the ends first tapered and then flared, so that the flame passing out through said eyes will be slightly restricted, and thus given a tendency toward increased velocity, and after such tendency is imparted thereto said flame is left free to spread slightly by the flare of the eye. The apertures formed in the eye afford a supply of fresh heated air to the products of combustion moving through the eyes, which air has an opportunity to com-- mingle with the gases before their discharge from the eye, due to the presence of the apertures near the intake end of the respective eye and further due to the restriction of the eye, which commingling insures the more effectual consumption of the combustible gases.

In operation it is my desire to prevent the escape of combustible gases, and I have there fore provided for the supplying of heated air for insuring consumption of such gases, and I have further provided against the excessive draft at the time of discharge of the greatest amount of gases from the fire-box. WVhen the doors 12 are swung open for per- As soon mitting charging of the lire-box with a fresh supply of coal, the steam-supply, as above described, will eflect a discharge of a relatively large quantity of heated air into the firebox, which tends to prevent the admission of a chilling charge of air through the doorway. At the same time the damper 36 opens automatically, as above described, and the admission of air to the stack 37 from the flue 35 will tend to prevent any excessive increase in the draft, so that when coal is thrown into the fire-box the gases rising therefrom will not be given an impetus, but will rather be restricted and retained either within the flrebox itself or within the heating-chamber 4 until the doors 12 are closed, and the supply of air will continue after the doors have been closed for a sufficient length of time to insure consumption of the said gases. Suitable apertures -5 are formed through the rear partition of the bridge-wall for each of the eyes 6 and 7, and said apertures are arranged to converge toward the chamber 4 for supplying air to the products of combustion entering said chamber for aiding in sustaining combustion.

In practice I fmd that in order to secure the best possible results and obtain the greatest amount of heat from a minimum amount of fuel it is necessary to employ a hot-air blast, such as is above described, for supplying air to the lire-box. This blast drives the gases into the draft-eyes 6 and 7 with considerable velocity and the reduced discharge ends of said draft-eyes retard the products for allowing an opportunity for perfect combustion, and in order to support such combustion heated air is supplied through the apertures 9 to the interior of the draft-eyes. Extensive experiments have established the fact that a'restricted supply through the apertures 9 will fail to produce a perfect combustion of the products discharged through the draft-eyes, and hence I have provided within the bridge-wall what might be termed an enlarged storagechamber for hot air, and by the devices above described I supply the storage-chamber with an ample quantity of heated air under suflicient pressure to cause the same to enter the draft-eyes 6 and 7 whenever a blast of gases is driven therethrough. I find that by having the chamber within the bridgewall relatively large and completely surrounding each of the draft-eyes the gases passing through said eyes will be supplied with a sufficient quantity of air to produce practically perfect combustion and all combustible gases will be consumed.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a furnace, the combination with an inclosing casing and a boiler arranged there in, of a bridge-wall within said casing, drafteyes extending through said bridge-wall outside the vertical plane of the longitudinal axis of said boiler, and a draft-eye extending through said bridge-wall within the vertical plane of the longitudinal axis of said boiler, all of said draft-eyes being spaced approximately the same distance from the boiler.

2. In a furnace, the combination with an inclosing casing and a boiler arranged therein, of a bridge-wall arranged transversely of said casing, relatively large drafteyes extending through said bridge-wall outside the vertical plane of the longitudinal axis of said boiler, and a relatively small draft-eye extending through said bridge-wall beneath said boiler.

33. In a furnace, the combination with a fire-box and means for supplying air thereto, of a pipe adapted to discharge steam through said air-supply means, a valve-casing arranged intermediate the length of said supply-pipe, a piston within said valve-casing, a spring pressing said piston in a direction opposite to the flow of the steam for cutting off the supply of steam, a port aflording communication of steam from the steam-supply pipe to said valve in position for adding the pressure thereof to the pressure of the spring, and means for cutting ofl the supply through said port.

4. In a furnace, the combination with a lire-box and means for supplying air thereto, of a pipe adapted to discharge steam through, said air-supply means, a controlling-valve casing disposed'in the length of said pipe, a piston within said casing directly receiving the pressure of the steam, a spring pressing said piston in an opposite direction to the flow of the steam, the pressure exerted by the spring being slightly less than the steam-pressure, a valve connected with said piston adapted to be moved in position for cutting off the steam-supply, a port affording communication between the steam-supply and said casing in position for adding-the pres sure of the steam conveyed by said port to the pressure of the spring upon said piston, and means for exhausting the steam within the port.

5. In a furnace, the combination with a fire-box and means for supplying air thereto, of a steam-supply pipe adapted to discharge through said air-supply means, a controllingvalve casing disposed in the length of said steam-supply pipe, a piston within said casing directly receiving the pressure of the steam, a spring pressing the said piston in an opposite direction to the flow of the steam, a

valve adapted to be actuated by said piston for cutting off the steam-supply, a port com municating between the steam-supply and said casing, and positioned for adding the pressure of the steam conveyed by the port to the pressure of said spring, and a valve controlling the admission of steam through said port.

6. In a furnace, the combination with a fire-box and means for supplying air thereto, of a pipe adapted to discharge a fluid under pressure through said air-supply means, a valve interposed in the length of said pipe and acting longitudinally of said pipe against the pressure therein for preventing discharge of the fluid from said pipe, a by-pass leading from the pressure side of said valve to the opposite side thereof for maintaining the valve upon its seat, and means for cutting off the supply of fluid through said by-pass and for exhausting the fluid in the rear of the valve for permitting the valve to be moved by the direct pressure in said pipe, such movement of the valve permitting discharge of fluid from said pipe.

7. I11 a furnace, the combination with a lire-box and means for supplying air thereto, of a steam-supply pipe adapted to discharge through said air-supply means, a valve casing interposedlongitudinally in the length of said steam-supply pipe, a piston movable longitudinally of said casing arranged to receive the pressure of steam in said supplypipe, said casing being provided with a lateral opening for the discharge of steam, a valve connected with said piston for closing said lateral opening, a spring pressing said piston in a direction opposing the pressure of the steam, a by-pass communicating between the steam-supply pipe and said valve-casing in position for adding the pressure of the steam supplied through said by-pass to the pressure of said spring, and means governing the steam in said bypass.

8. In a furnace, the combination with a fire-box, and means for supplying air thereto, of a pipe adapted to discharge a fluid under pressure through said supply means, a valve interposed in the length of said pipe in position for receiving the full impact of the fluid, a spring pressing said valve against the pressure of the fluid within said pipe, the pressure of said spring being less than the pressure within the pipe, and a by-pass leading from said pipe and communicating with said valve in position for adding the pressure of the fluid to that of said spring for moving the valve against the pressure of the fluid in said pipe, and means for controlling the fluid within said by-pass.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WVILLIAM N. COX. 

